Topographic maps and satellite images
Explanation:
A topographic map represents earth's surface features like land forms and structures, rivers and lakes, mountains and hills, elevations and other natural features along with man-made artificial features like cities, buildings, monuments, roads, bridges etc. These are formed by contour lines.
Topographic maps are printed with revision dates to observe the changes happening on the Earth's surface. Various land forms keeps changing due to natural and man-made causes and these needs to be updated accordingly to provide accurate details.
A satellite image provides details of the earth aerially from space. These provides details of a land form or any earth structure currently.
By comparing with older satellite images or topographic maps with the current one, the changes which occurred over time can be observed.
Tons of rain can cause an ecosystem to flood, killing species that are not meant to withstand lots of water. Ocean temperature can slow down or speed up evaporation, affecting precipitation rates.
Hope I helped!
~ Zoe
The answer is D
One way to remember this is when you are building a bridge there is one piece right in the middle that keeps the whole thing from collapsing that is called the key-stone. If a keystone species goes extinct then the rest of the ecosystem will crumble around it.